Cryosurgical delivery and application of liquified gas coolant



United States Patent [72] Inventor Michael D. Bryne Vernon, Connecticut [21] Appl. No. 683,351 [22] Filed Nov. 15, 1967 [45] Patented Oct. 20, 1970 [73] Assignee Brymill Corp.

Vernon, Connecticut a corporation of Connecticut [54] CRYOSURGICAL DELIVERY AND APPLICATION OF LIQUIFIED GAS COOLANT 3 Claims, 5 Drawing Figs.

[52] U.S. Cl 128/303.1, 62/293, 62/371,222/394, 239/337,128/173 [51] Int. Cl .,A61b 17/36 [50] Field ofSearch 128/303, 303.1, 355,225, 173, 239, 2.1; 239/337, 573, 577, 579'.222/394:62/293.371.52:138/114 [56] References Cited UNITED STATES PATENTS 1,899,749 2/1933 Deutsch 128/173UX 2020,860 11/1935 Touborg 138/114X 2,331,117 10/1943 Goodhueet a1. 128/173X Journal of the Amer. Med. Assoc; Whitehouse; Vol. XLlX; No.6, 1907; pgs. 371 377; Copy in Grp 330; 1128/3031 Title of article Liquid Air in Dermatology" Primary Examiner-Anton O. Oechsle Assistant ExaminerRichard J. Apley Attorney-Melvin Pearson Williams ABSTRACT: A self-contained, mobile, compact, untethered cryosurgical instrument is provided in which liquified gas coolant in a container with heat conducting walls is pressurized by ambient temperature for delivery to a lesion to be necrotized. The coolant is discharged in a controlled spray in one embodiment; the delivery tube includes a vent tube coaxially spaced therefrom in other embodiments. Freezing to tissue is overcome with Teflon" coatings.

Patented Oct. 20, 1970 Sheet of 2 rHHI IHU CRYOSURGICAL DELIVERY AND APPLICATION OF LIQUIFIED GAS COOLANT CROSS-REFERENCE TO RELATED APPLICATIONS Apparatus in accordance with the present invention may be utilized in conjunction with the method and means of necrotizing lesions disclosed in a copending application of the same inventor, entitled NECROTIZING LESIONS CRYO- SURGICALLY, Ser. No. 728,5 36, filed on May 13, 1968, now abandoned.

BACKGROUND OF THE INVENTION l. Field of Invention This invention relates to cryosurgery, and more particularly to the delivery and application of liquified gas coolant to living tissue in order to necrotize the same.

2. Description of the Prior Art It has long been known in the prior art to use liquified gas (such as helium, nitrogen, oxygen, air, freon, zenon, carbon dioxide, etc.) to freeze healthy or diseased tissue, and thereby necrotize the tissue. For instance, one well-known use of liquified gas in cryosurgery is the removal of lesions. both on the skin or internally. Usually, the object is to remove the lesion by destroying the tissue; in other cases, the object is the destruction of the tissue while maintaining adjacent portions of the tissue structure in place, such as in the walls of vital organs. As used herein, lesion means both diseased and healthy tissue which is to be frozen; the destruction of lesions includes removal of healthy tissue for cosmetic purposes, and killing of tissues as a complementary modality to surgical procedures.

Heretofore, the liquified gas has been delivered through an insulated tube to an applicator. The delivery of the liquid to the applicator has been accomplished by using pressure within the reservoir containing the liquid to force the liquid out of the reservoir. The creation of pressure within the reservoir has been achieved in several different ways. A first and perhaps most widely used method of creating pressure in a liquified gas container is to place an electric heater within the reservoir of the liquid, thereby raising the liquid to a boiling temperature so that a gas pressure is created. The liquified gas, as it vaporizes, creates sufficient pressure to force the liquid out of the reservoir. A different type device utilizes external gas pressure (such as a separate tank of compressed dry air, or other suitable source of compressed gas) to force the Iiquified gas coolant out of the reservoir.

All of the before described devices require connections either to a source of fluid pressure or to electrical energy, or on the other hand, are bulky due to the need of a heat exchanger or batteries. Additionally, the need for adjunct equipment makes such devices expensive, complex and cumbersome. Such devices are not well adapted to portable office use for small dermatological applications, nor for certain internal applications which involve small spaces or tortuous routes. Furthermore, cumbersome devices of the type described tend to absorb too much space in already overcrowded operating rooms.

Another characteristic of previously known cryosurgical devices is the need to have a long delivery tube which must be insulated in order to achieve an adequate percentage of liquid nitrogen delivered to the application end (the distal end) of the device. The insulated delivery tubes which have been found to be practical in the prior art usually comprise coaxial evacuated Bellows-type tubing, which is usually comprised of stainless steel. Therefore, these tubes are quite stiff and offer substantial resistance in mobility to the surgeon using the device. It can readily be understood that it is essential that the surgeon be able to position the device very accurately in order to freeze the selected area without freezing adjacent areas. For instance, a lesion on an eyelid presents a near probability of doing great damage to the eye unless precision application is possible. Therefore, the positioning of the equipment relative to the patient is critical. Moreover, many lesions are of a very complex shape, and must be addressed from different angles in order to adequately treat all of the portions thereof. Furthermore, anatomical irregularities of the body relative to the positioning of the lesion make mobility of instrumentation critical. It is therefore apparent that the stiff delivery tubes known to the prior art hinder the surgical usage of the equipment, and render it difficult to provide adequate lesion removal. Certain other devices have attempted to overcome stiffness by using flexible plastic tubing; however, at temperatures capable of freezing human tissue, these devices become stiffer than the evacuated metallic types, and are therefore relatively useless.

So great is the problem with insulated delivery tubes that various devices have been composed for overcoming the need for such delivery tubes. One such device provides liquid nitrogen in a probe handle, and utilizes an external source of compressed gas which will not .freeze much above liquid nitrogen temperature to be cooled by the nitrogen and mixed with nitrogen gas so as to provide a cold gas application to the tube and applicator tip which is cooled sufficiently so that when the applicator tip is applied to a lesion, it will freeze it. However this device, though providing a flexible tube, is nonetheless tethered and the device itself is so large, relative to the amount of nitrogen in it, that its application is limited to the removal of extremely small lesions. Furthermore, the device is so complex as to render it extremely difficult to construct, and it may also have a tendency for unreliable operation.

A different problem in the cryosurgical freezing of tissue is a need for good heat exchange. Most devices known to the prior art utilize liquid nitrogen to cool a probe, and the probe in turn is applied to the lesion. This has taken a variety of forms, and in the more sophisticated cryosurgical apparatus known to the prior art, the probe applicator tip is sprayed with liquid nitrogen fed through the inner tube of a coaxial tube assembly, the outer tube venting the nitrogen gas away from the area of the applicator tip.

SUMMARY OF THE INVENTION Objects of the invention include:

Provision of a self-contained untethered cryosurgical liquitied gas coolant delivery system;

Provision of mobile, readily oriented, compact cryosurgical instruments.

According to the present invention in one form, a self-pressurizing, compact, untethered cryosurgical instrument comprises a reservoir composed of a material which has a relatively high heat conductivity, the reservoir adapted to receive a liquified gas, the gas being boiled by ambient temperatures at a sufficient rate so as to provide an adequate flow of liquid (as a result of a vaporization pressure of the liquid, as it vaporizes) to be useful in the freezing of living tissue. According to a specific aspect of the present invention, the flow of liquid from the reservoir is controlled by selectively venting the pressurized vapor of the liquid when no flow is desired, and blocking the vent when a flow of liquid is desired. Because the instrument is so compact as to be completely held in the surgeons hand, the liquid source is within a few inches of the application field, and therefore avoids complex insulation of the delivery tube without significant vaporization of the coolant before it is utilized.

The foregoing and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of preferred embodiments thereof as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a partially sectioned, broken away side elevation view of one embodiment of the present invention adapted for unvented application of cryosurgical coolant;

FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1;

FIG. 3 is a partially sectioned, broken away side elevation view of another embodiment of the present invention including venting of vapor from the coolant application area;

FIG. 4 is a partially sectioned and broken away plan view of the embodiment of FIG. 3; and

FIG. 5 is a rear elevation view of the embodiment of FIG. 3, partially sectioned and broken away.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, one embodiment of a cryosurgical liquified gas coolant delivery and application system in accordance with the present invention comprises a container within which the liquified gas coolant is placed. The container 20 is threaded (22) so as to releasably engage a cover assembly 24, which has matching threads. A delivery tube 26, fitted through a hole 27 in the cover assembly 24. has a bend 28 therein so as to provide an external. substantially horizontal portion 32. At the external end of the tube 26 there is a fitting 34, which may comprise any suitable compression or flared fitting known to the art, a number of which are commercially available. This fitting may have any suitable application means 36 attached thereto; in accordance with one aspect of the present invention, the application means 36 comprises a nozzle formed by drilling a suitable hole in a blind cap or plug, to provide a controlled spray.

The cover assembly 24 has a pressure control vent hole 38 therein, which provides gaseous communication with a passage 40 in a handle assembly 42. The handle assembly 42 is affixed to the cover assembly 24 by any suitable means such as screws 44 (see also FIG. 2). The passage 40 joins and is axially aligned with a further passage of a larger diameter 46. Within the passage 46 is a passage closure means 48 which may comprise a cylindrical barrel portion 50 being conical at one end 52, and having a cap portion 54 at the other end. The closure means 48 may be resiliently urged to the left in FIG. I by any suitable means such as a spring 56, one end of which is inserted in a hole 58 within the closure means 48. The other end of the spring 56 may be fastened to the handle assembly 42 by a screw 60. With the closure withdrawn to the left (as seen in FIG. 1), the passage 46 is in communication with a passage 62 which passes any gas therein out of a port 64 to atmosphere.

In operation, the container 20 is filled with liquified gas coolant, such as liquid nitrogen, to a suitable level. The container 20 may consist of metal or glass, or other suitable material capable of conducting heat from ambient atmosphere to the liquid therein. This causes some of the liquid to boil, resulting in the generation of gas. So long as the closure means 48 is left in its rest position (to the left, as shown in FIG. 1), the gas is vented to atmosphere through the passages 40, 46, 62. However, when delivery of coolant to tissue is desired, the nozzle 36 may be directed by the surgeon (holding the instrument by the main shank portion 65 of the handle assembly 42) toward the tissue, and the surgeon may push the closure means 48 (to the right in FIG. 1), thus causing the conical end 52 to sealably engage a chamfered surface 66 at the intersection of the passages 40, 46, 62. It has been found that relatively light force applied by the surgeons thumb to the button end 54 of the closure means 48 will positively block the vent passages 40, 46, so that pressure will build up within the container 20. This pressure forces liquid coolant into the delivery tube 26 and through the nozzle 36.

In order to prevent the loss of pressure within the container 20, and to prevent vapor from escaping about the cap and handle assemblies 24, 42, suitable seals are provided. A gasket 68 (FIGS. I and 2) provides a seal between the container 20 and the cap assembly 24. The gasket 68 may be fitted tightly into the cap assembly 24 as is well known in the art. It may be of any suitable material, depending on the temperature of the liquid coolant chosen; cotton, cork and other natural products (except rubber) as well as silicon rubber and Teflon are suitable materials even at liquid nitrogen temperatures.

The delivery tube 26 is preferably welded to the hole 17 so as to seal the joint as well as to give structural support to the tube 26. However, other modes of attachment and sealing may be utilized.

To provide a seal at the joinder 70 of the handle assembly 42 with the cap assembly 24, some modicum of sealant is required. For instance, a thin sheet of Teflon, coated on each side with silicon (vacuum) grease, works quite well. Other means may be used to suit any design criteria in accordance with the skill of the art.

The embodiment of the invention thus described with respect to FIGS. 1 and 2 comprises a completely self-contained, untethered cryosurgical instrument. It can be directed toward a field of application from many angles without requiring repositioning of the subject, or the rolling around the room of a console (as is true of prior devices). It can, by suitable choice of length of delivery tube 32, be used to reach into small cavities, or by bending the delivery tube 32 (which is not possible with prior devices), be used to reach around corners or traverse tortuous routes.

A second embodiment of the present invention is adapted for use where venting of coolant vapor from the point of application is required. As seen in FIGS. 3-5, this is identical to the embodiment of FIGS. 1 and 2 except that a vent tube is provided coaxially with and externally of the delivery tube portion 32. The vent tube 100 may be press-fit into a passage I02 in the handle assembly 42, with an extension 104 of the passage 102 venting the tube 100 to atmosphere through the main shank portion 65 of the handle assembly 42. Note that the vent passages 62 (FIGS. 1 and 2) and 104 (FIGS. 35) vent cold vapor away from the treatment area, and downwardly so as not to injure the patient, nor to injure nor obscure the vision of the surgeon.

The delivery tube 26 may be assembled to the vent tube 100 by slotting the vent tube 100 at the bottom thereof to the left of the delivery tube portion 30 (as seen in FIG. 3). The tube 100 may thereafter be welded shut, or may remain slotted, since the tube 26 and the handle assembly 42 are sealed with respect to the cap assembly 24, and no leakage will take place therebetween, as described hereinbefore with respect to FIGS. 1 and 2.

The apparatus of FIGS. 3-5 may have a fitting thereon so as to permit connecting chambers of the type described and claimed in my aforementioned copending application attached thereto, or regular applicator tips known to the prior art may be threaded thereon. On the other hand, the invention may also be practiced by fastening any suitable application means to either or both of the tubes 32, 100, in any suitable way, or by forming the end of tube 100 in a suitable fashion as an applicator. The pertinent fact is that the invention may use a nonvented spray, or vented application of various types.

Although the invention has been shown and described with respect to preferred embodiments thereof, it should be un derstood by those skilled in the art that the foregoing and other changes and omissions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.

lclaim:

1. A cryosurgical instrument comprising:

means including a reservoir adapted to receive a quantity of liquified gas coolant for providing a source of boiling liquified gas coolant;

a delivery tube having one end adapted to be immersed in the liquified gas coolant within said reservoir, and capable of conducting the coolant outwardly of said reservoir to the other end thereof;

handle means having a downwardly extending portion adapted to be grasped by the hand of an operator for holding said instrument, said reservoir engaged with said handle means when in operation; and

means for selectively pressurizing said reservoir, in the presence of the coolant, to thereby force coolant along said delivery tube, said means including a normally open vent extending from a portion of said reservoir above the level of coolant therein to ambient atmosphere through a passage within said handle means, said vent including a portion at least partially coextensive with the downwardly extending portion of said handle means, and operator controlled means including a moveable member disposed in said handle means for selectively blocking said vent so therethrough to a point distant from the delivery end of said delivery tube, said application vent passage venting gaseous flow through said handle means.

that pressure builds up in said reservoir as a result of vaporization of the coolant. 2. The cryosurgical instrument according to claim 1 additionally comprising:

means including said delivery tube and an application vent 3. The cryosurgical instrument according to claim It addi- 5 tionally comprising:

means including said delivery tube and an application vent tube adapted to receive a cryogenic applicator for assistance in the utilization of said coolant for the cryosurgical treatment of tissue. said application vent tube having at least a portion thereof disposed adjacent to said delivery tube at points of said delivery tube external of said reservoir. at least a portion of said application vent tube including a second passage through said handle means. 

